The present invention relates generally to piston type seal configurations and specifically to a sandwich shaped piston seal for sealing multiple mandrels within the surrounding cylindrical body of a multiple mandrel well packer.
Multiple mandrel production packers used in the oil and gas well industry have a generally cylindrical outer body and two or more tubular members or mandrels which pass through the interior of the body parallel to the longitudinal axis of the body. By providing the ends of the mandrels of differing lengths, the multiple mandrel packer can be used to produce from multiple zones which are packed off within the well bore. In order to prevent crossover of well fluids and to insure the integrity of the packer seal, it is necessary to seal the multiple mandrels within the cylindrical body of the tool.